Ice making apparatus and refrigerator having the same

ABSTRACT

An ice making apparatus capable of reducing an ice making time be rapid cooling of an ice making tray thereof while guaranteeing the making of transparent ice and a refrigerating having the ice making apparatus. The ice making apparatus includes the ice making tray to freeze water filled therein so as to make ice, and a cold air guiding device to guide cold air to a lower surface of the ice making tray. The cold air guiding device includes a cold air guiding plate installed below the ice making tray to be spaced apart from the lower surface of the ice making tray, and a plurality of protrusions provided at an upper surface of the cold air guiding plate to guide the cold air flowing along the upper surface of the cold air guiding plate in a direction toward the lower surface of the ice making tray.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Korean Patent Applications No. 10-2006-0076434, filed on Aug. 11, 2006 and No. 10-2007-0054431, filed on Jun. 4, 2007 in the Korean Intellectual Property Office, the disclosures of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an ice making apparatus for the making of ice and a refrigerator having the ice making apparatus. More particularly, to an ice making apparatus which can achieve an improvement in the ice making performance thereof by virtue of rapid cooling of an ice making tray, and a refrigerator having the ice making apparatus.

2. Description of the Related Art

Korean Patent Registration Publication No. 10-0565621 discloses a conventional refrigerator having an upper refrigerating compartment and a lower freezing compartment. The refrigerator further includes an ice making chamber provided in the refrigerating compartment for making of ice.

The ice making chamber communicates with the freezing compartment through a cooling duct to receive cold air supplied upward from the lower freezing compartment. The ice making chamber is internally provided with an ice making apparatus for making ice and an ice storage container having an ice discharge function.

The ice making apparatus includes an ice making tray to make ice using water supplied from an external water supply source, an ice separator to discharge the ice from the ice making tray into the ice storage container, and a drive motor to drive the ice separator. The ice making tray is installed with a heater, which serves to slightly melt the ice in order to separate the ice from the ice making tray.

The above-described conventional refrigerator has a problem in that it requires an excessively long time to make ice because an ice making operation must be performed only after an interior temperature of the ice making chamber drops by cold air supplied there to until it reaches a desired freezing condition. Specifically, the conventional refrigerator has a problem in that an excessively long time is required for the cooling of the ice making tray.

Furthermore, in the above-described ice making apparatus provided in the conventional refrigerator, the ice making tray should be heated by the heater to guarantee successful separation of the ice from the ice making tray. Therefore, to perform an ice making operation again after separation of the ice, it is essential to remove the heat remaining in the ice making tray, and therefore requires an increase in the cooling time of the ice making tray.

SUMMARY OF THE INVENTION

Accordingly, it is an aspect of the present invention to provide an ice making apparatus, which can achieve a reduced ice making time by virtue of rapid cooling of an ice making tray thereof, and a refrigerator having the ice making apparatus.

It is another aspect of the present invention to provide an ice making apparatus, which can achieve rapid removal of residual heat in an ice making tray after separation of ice, and a refrigerator having the ice making apparatus.

It is yet another aspect of the present invention to provide an ice making apparatus, which can guarantee the making of transparent ice by allowing water received in an ice making tray to be gradually frozen from the bottom to the top, and a refrigerator having the ice making apparatus.

Additional aspects and/or advantages of the invention will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the invention.

The foregoing and/or other aspects of the present invention are achieved by providing an ice making apparatus including an ice making tray to freeze water filled therein to make ice, and a cold air guiding device to guide cold air to a lower surface of the ice making tray, wherein the cold air guiding device includes a cold air guiding plate installed below the ice making tray to be spaced apart from the lower surface of the ice making tray, and a plurality of protrusions provided at an upper surface of the cold air guiding plate to guide the cold air flowing along the upper surface of the cold air guiding plate in a direction toward the lower surface of the ice making tray.

According to an aspect of the present invention, the cold air guiding device further includes first and second side guiding portions extending upward from opposite sides of the cold air guiding plate, respectively, to allow the cold air to flow in a space defined between the lower surface of the ice making tray and the upper surface of the cold air guiding plate.

According to an aspect of the present invention, the cold air guiding device further includes a third side guiding portion having opposite ends connected, respectively, to first ends of the first and second side guiding portions, the third side guiding portion including a cold air inlet to be connected to a cold air duct.

According to an aspect of the present invention, the cold air guiding device is opened at an opposite side of the third side guiding portion.

According to an aspect of the present invention, the plurality of protrusions are formed lengthwise in a direction intersecting with a flow direction of the cold air.

According to an aspect of the present invention, the plurality of protrusions include a triangular cross section.

According to an aspect of the present invention, each of the protrusions includes opposite ends to come into contact with the first and second side guiding portions, respectively.

The plurality of protrusions are spaced apart from each other in the flow direction of the cold air and alternately arranged at opposite sides of the cold air guiding plate.

It is another aspect of the present invention to provide a refrigerator including a body having at least one storage compartment and an ice making apparatus mounted in a partitioned space within the storage compartment, wherein the ice making apparatus includes an ice making tray to freeze water filled therein to make ice and a cold air guiding device to guide cold air to a lower surface of the ice making tray, and the cold air guiding device includes a cold air guiding plate installed below the ice making tray to be spaced apart from the lower surface of the ice making tray, and a plurality of protrusions provided at an upper surface of the cold air guiding plate to guide the cold air flowing along the upper surface of the cold air guiding plate in a direction toward the lower surface of the ice making tray.

It is yet another aspect of the present invention to provide an ice making apparatus comprising: an ice making tray to freeze water filled therein to make ice, and a cold air guiding device having a cold air flow path to guide cold air to a lower surface of the ice making tray, wherein the cold air flow path of the cold air guiding device has a cross sectional area decreasing from the upstream to the downstream.

The cold air guiding device comprises: a cold air guiding plate installed below the ice making tray to be spaced apart from the lower surface of the ice making tray; and a plurality of side guiding portions extending upward from opposite sides of the cold air guiding plate.

The cold air guiding plate comprises a plurality of stepped portions configured such that the heights of upper surfaces of the stepped portions initially gradually increase and again, gradually decrease from the upstream to the downstream.

The cold air guiding device comprises a plurality of triangular ribs formed in the cold air flow path to connect an upper surface of the cold air guiding plate and one of the side guiding portions to each other, for creating an eddy of cold air.

The plurality of triangular ribs gradually increase in size from the upstream to the downstream of the cold air flow path.

The cold air flow path of the cold air guiding device has a cross sectional area initially decreasing and again increasing from the upstream to the downstream thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a sectional view illustrating a refrigerator having an ice making apparatus according to an embodiment of the present invention;

FIG. 2 is a front view of the refrigerator having the ice making apparatus according to an embodiment of the present invention;

FIG. 3 is a detailed view of the ice making apparatus according to an embodiment of the present invention;

FIG. 4 is a sectional view taken along the line IV-IV′ of FIG. 3;

FIG. 5 is a perspective view illustrating a first embodiment of a cold air guiding device included in the ice making apparatus according to the present invention;

FIG. 6 is a perspective view illustrating an alternative embodiment of the cold air guiding device shown in FIG. 5;

FIG. 7 is a perspective view illustrating a second embodiment of the cold air guiding device included in the ice making apparatus according to the present invention; and

FIG. 8 is a sectional view of the ice making apparatus according to the present invention, which employs the cold air guiding device shown in FIG. 7.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below to explain the present invention by referring to the figures.

FIGS. 1 and 2 illustrate a refrigerator having an ice making apparatus according to an embodiment of the present invention. As shown in FIGS. 1 and 2, the refrigerator comprises a body 10, which is divided into an upper refrigerating compartment 11 and a lower freezing compartment 12 by means of a partition wall 13.

The refrigerating compartment 11 and the freezing compartment 12 each have open front sides. The upper refrigerating compartment 11, as shown in FIG. 2, is opened and closed by first and second refrigerating compartment doors 14 and 15. The lower freezing compartment 12 is opened and closed by a freezing compartment door 16. The first and second refrigerating compartment doors 14 and 15 are hingedly coupled with opposite sides of the body 10 in a pivotally rotatable manner, respectively. Therefore, the first and second refrigerating compartment doors 14 and 15 are rotatable leftward and rightward, respectively, to open and close the refrigerating compartment 11. The freezing compartment door 16, as shown in FIG. 1, is coupled with a drawer type storage container 16 a mounted in the freezing compartment 12. The freezing compartment door 16 opens and closes the freezing compartment 12 via forward and rearward movements thereof.

Although not shown in the drawings, alternatively, the freezing compartment door 16 may be hingedly coupled with the body 10 so that it opens and closes the freezing compartment 12 via pivotal rotation thereof.

A freezing compartment evaporator 17 to cool the freezing compartment 12 and a freezing compartment circulating fan 18 to circulate cold air within the freezing compartment 12 are mounted in a space defined in a rear region of the freezing compartment 12. The space where the freezing compartment evaporator 17 and freezing compartment circulating fan 18 are mounted, is separated from the remaining interior space of the freezing compartment 12 by means of an inner panel 19 which is also mounted in the rear region of the freezing compartment 12. The inner panel 19 internally defines a cold air circulating path 20 for the circulation of cold air in the freezing compartment 12. The cold air circulating path 20 guides the cold air blown by the freezing compartment circulating fan 18 to evenly distribute and supply cold air into the freezing compartment 12.

A refrigerating compartment evaporator 21 to cool the refrigerating compartment 11 and a refrigerating compartment circulating fan 22 to circulate cold air within the refrigerating compartment 11 are mounted in a space defined in a rear region of the refrigerating compartment 11. The space where the refrigerating compartment evaporator 21 and refrigerating compartment circulating fan 22 are mounted, is separated from the remaining interior space of the refrigerating compartment 11 by means of an inner panel 23 which is also mounted in the rear region of the refrigerating compartment 11. The inner panel 23 internally defines a cold air circulating path 24 for the circulation of cold air in the refrigerating compartment 11. As will be understood from the above-described configuration, both the freezing compartment 12 and the refrigerating compartment 11 are cooled by the respective evaporators 17 and 21.

An ice making chamber 26 is provided in an upper corner region of the refrigerating compartment 11 in such a manner that it is separated from the remaining interior space of the refrigerating compartment 11 by means of an insulation wall 7. To maintain the ice making chamber 26 at a freezing temperature, cold air is supplied into the ice making chamber 26 from the freezing compartment 12 that is defined in the lower portion of the body 10. Thus, a cold air supply path 27 and a cold air return path 28 (See FIG. 2) are provided in the rear region of the body 10. The cold air supply path 27 is used to supply the cold air generated by the freezing compartment evaporator 17 into the ice making chamber 26, and the cold air return path 28 is used to return the air having passed through the ice making chamber 26, toward the freezing compartment evaporator 17. A blowing fan 29 is mounted below the cold air supply path 27 to forcibly blow the cold air, discharged upward from the freezing compartment evaporator 17, into the cold air supply path 27.

The ice making chamber 26 comprises an ice making apparatus 30 to make ice, an ice storage container 60 to store the ice made by the ice making apparatus 30, the ice storage container 60 having an ice outlet 61, an ice transfer device 70 to discharge the ice from the ice making chamber 26, and an ice crushing device 80 to crush the ice to be discharged through the ice outlet 61.

The first refrigerating compartment door 14, as shown in FIG. 1 comprises a discharge chute 65 to guide the ice discharged from the ice outlet 61 of the ice storage container 60, to an outside of the first refrigerating compartment door 14. The first refrigerating compartment door 14 comprises an ice receiving space 66 in a front surface thereof, to receive the ice discharged through the discharge chute 65. According to an embodiment of the present invention, the discharge chute 65 is obliquely formed in a protruding portion 67 that inwardly protrudes from an inner surface of the first refrigerating compartment door 14. The position of the discharge chute 65 is determined so that an entrance thereof coincides with the ice outlet 61 of the ice storage container 60 in a state wherein the first refrigerating compartment door 14 is closed.

The ice making apparatus 30, as shown in FIGS. 3 and 4, is secured in an upper portion of the ice making chamber 26. The ice making apparatus 30 comprises an ice making tray 31 to make ice by use of water supplied from an external water supply source, an ice separator 32 to discharge the ice from the ice making tray 31, a drive motor 33 to operate the ice separator 32, and a heater 34 to heat the ice making tray 31 when it is desired to discharge the ice from the interior of the ice making tray 31. The ice making apparatus 30 further comprises a cold air guiding device 40 to allow the cold air which is supplied from the lower freezing compartment 12 of the body 10 into the ice making chamber 26, to be directly supplied to a lower side of the ice making tray 31.

The interior of the ice making tray 31, as shown in FIG. 3, is divided into a plurality of ice making spaces 31 b by means of a plurality of partitions 31 a to make a plurality of ice pieces at a same time. As shown in FIG. 4, for example, the ice making tray 31 comprises a semi-circular cross section.

The ice separator 32 comprises a rotating shaft 32 a which is rotatably coupled with an upper end position of the ice making tray 31, and a plurality of scrapers 32 b radially extended from the rotating shaft 32 a. The number of scrapers 32 b correspond to the number of ice making spaces 31 b so that they are introduced into the respective ice making spaces 31 b to discharge the ice pieces from the ice making spaces 31 b. In operation of the ice separator 32, specifically, when the rotating shaft 32 a is rotated by the drive motor 33, the scrapers 32 b are simultaneously rotated by an angle of 360 degrees, so as to scrape out the ice pieces from the respective ice making spaces 31 b. During the separation of the ice pieces, the heater 34 operates to slightly heat the ice making tray 31, to facilitate easy separation of the ice pieces from the ice making spaces 31 b.

FIGS. 3 to 5 illustrate the cold air guiding device 40 according to a first embodiment of the present invention. The cold air guiding device 40 which guides the cold air to the lower side of the ice making tray 31, comprises a cold air guiding plate 41 installed below the ice making tray 31 to be spaced apart from a lower surface of the ice making tray 31 by a predetermined distance, first and second side guiding portions 42 and 43 extending upward from opposite sides of the cold air guiding plate 41, and a third side guiding portion 44 to connect the first and second side guiding portions 42 and 43 to each other, the third side guiding portion 44 comprises a cold air inlet 45. The first, second and third side portions 42, 43 and 44 being integrally combined with the cold air guiding plate 41, for example. A cold air duct 46 is connected to the cold air inlet 45 of the third side guiding portion 44, to communicate with the cold air supply path 27 that is defined in the rear region of the body 10.

By use of the cold air guiding device 40, the cold air which is supplied from the lower freezing compartment 12 of the body 10 to the ice making chamber 26, is able to be first supplied to the ice making tray 31, to thereby directly cool the ice making tray 31.

The cold air guiding plate 41 comprises a plurality of protrusions 47 at an upper surface thereof, to guide the cold air flowing in the interior of the cold air guiding device 40 upward to the lower surface of the ice making tray 31. Therefore, the lower surface of the ice making tray 31 can be directly cooled by the cold air.

According to an embodiment of the present invention, the plurality of protrusions 47 extend lengthwise in a direction intersecting with a flow direction of the cold air, and are spaced apart from one another in the flow direction of the cold air. Each of the protrusions 47 comprises a triangular cross section suitable to easily guide the cold air upward (i.e. toward the lower surface of the ice making tray 31).

The protrusions 47 are not limited to the above-described configuration. Alternatively, the protrusions 47 may have a semi-circular cross section, or wing shape extending obliquely upward from the cold air guiding plate 41 so long as they can guide the cold air flowing along the upper surface of the cold air guiding plate 41 upward.

As shown in FIG. 5, each of the protrusions 47 comprises a length corresponding to a width of the cold air guiding plate 41, such that opposite ends thereof come into contact with the first and second side guiding portions 42 and 43, respectively. Alternatively, as shown in FIG. 6, protrusions 47′ are configured to have a length shorter than the width of the cold air guiding plate 41 and are arranged alternately at opposite sides of the cold air guiding plate 41.

Now, an operation for supplying cold air through the above-described cold air guiding device 40 will be explained.

When cold air is supplied into the ice making chamber 26 through the cold air supply path 27 provided in the rear region of the body 10, the cold air is successively supplied into the cold air guiding device 40 through the cold air duct 46 provided in the ice making chamber 26. Accordingly, the cold air supplied into the ice making chamber 26 is wholly supplied into the cold air guiding device 40.

The cold air supplied into the cold air guiding device 40, directly cools the lower surface of the ice making tray 31 while flowing along a path defined by the cold air guiding plate 41, first and second side guiding portions 42 and 43, and the lower surface of the ice making tray 31. After being used to cool the ice making tray 31, the cold air is discharged into the ice making chamber 26 through an opening 48 formed at a side of the cold air guiding device 40 opposite to the third side guiding portion 44. While flowing in the cold air guiding device 40, the cold air is guided upward by the plurality of protrusions 47 formed at the upper surface of the cold air guiding plate 41 as stated above. Therefore, the cold air collides with the lower surface of the ice making tray 31, so as to directly cool the lower surface of the ice making tray 31. As a result, the ice making apparatus 30 of the present invention can achieve more rapid cooling of the ice making tray 31 than conventional ice making apparatuses, thus resulting in a reduction in ice making time. Furthermore, with the direct cooling of the ice making tray 31 using the cold air, even when any heat emitted from the heater 34 remains in the ice making tray 31 after separation of the ice from the ice making tray 31, the heat can be removed rapidly and consequently, the ice making time can be more reduced.

With the above-described cold air supply operation, water received in a bottom region of the ice making tray 31 can be frozen earlier than that received in a top region of the ice making tray 31. Accordingly, the water received in the ice making tray 31 can be gradually frozen from the bottom to the top of the ice making tray 31. Thus, guaranteeing the making of transparent ice because air received in the ice making tray 31 can be discharged to the outside from the top of the ice making tray 31 in the course of freezing the water.

FIG. 7 is a perspective view illustrating a cold air guiding device according to a second embodiment of the present invention. FIG. 8 is a sectional view of the ice making apparatus using the cold air guiding device of FIG. 7. The cold air guiding device 140 according to the second embodiment, as shown in FIGS. 7 and 8, comprises a cold air guiding plate 141 installed below the ice making tray 31 to be spaced apart from the lower surface of the ice making tray by a predetermined distance, first and second side guiding portions 142 and 143 extending upward from opposite sides of the cold air guiding plate 141, and a third side guiding portion 144 to connect the first and second side guiding portions 142 and 143 to each other, the third side guiding portion 144 comprising a cold air inlet 145. The cold air inlet 145 of the third side guiding portion 144 is connected to the cold air duct 46 that is connected with the cold air supply path 27 formed in the rear region of the body 10.

The cold air guiding plate 141 comprises a plurality of stepped portions 141 a, 141 b, and 141 c having different heights of an upper surface. Specifically, the heights of the upper surfaces of the stepped portions 141 a, 141 b, and 141 c initially gradually increase and again, gradually decrease from the upstream to the downstream of the cold air flow path. Here, the cross sectional area of the cold air flow path initially gradually decreases and again, gradually increases from the upstream to the downstream thereof. With this configuration, in addition to efficiently guiding cold air toward the lower surface of the ice making tray 31, the cold air guiding plate 141 causes the maximum flow rate of cold air at a location below the central region of the ice making tray 31, thus enabling a rapid ice making operation in the central region of the ice making tray 31. This has the effect of making up for the weak point of the ice making tray 31 that conventionally has a slower ice making operation in the central region than the remaining region thereof.

The cold air guiding device 140 further comprises a plurality of triangular ribs 145 a, 145 b, and 145 c spaced apart from one another within the cold air flow path. The triangular ribs 145 a, 145 b, and 145 c define slopes to connect an upper surface of the cold air guiding plate 141 and the side guiding portion 143 to each other. The triangular ribs 145 a, 145 b, and 145 c have different sizes from one another. Specifically, the sizes of the triangular ribs 145 a, 145 b, and 145 c gradually increase from the upstream to the downstream of the cold air flow path. With this configuration, the triangular ribs 145 a, 145 b, and 145 c create an eddy of cold air, thereby improving the contact efficiency of cold air and the lower surface of the ice making tray 31.

As apparent from the above-description, the present invention provides an ice making apparatus, which can achieve rapid cooling of an ice making tray thereof as a result of supplying cold air directly to a lower surface of the ice making tray by way of a cold air guiding device. Accordingly, the present invention has the effect of achieving a reduced ice making time.

Further, according to an embodiment of the present invention, the cold air is directly injected to the lower surface of the ice making tray to cool the ice making tray. Therefore, even if any heat emitted from a heater remains in the ice making tray after separation of ice from the ice making tray, the heat can be removed rapidly.

Furthermore, since the lower surface of the ice making tray can be directly cooled by the cold air, water filled in the ice making tray can be gradually frozen from the bottom to the top. As a result, the making of transparent ice can be accomplished.

Although a few embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents. 

1. An ice making apparatus comprising an ice making tray to freeze water filled therein to make ice, and a cold air guiding device to guide cold air to a lower surface of the ice making tray, wherein the cold air guiding device comprises: a cold air guiding plate installed below the ice making tray to be spaced apart from the lower surface of the ice making tray; and a plurality of protrusions provided at an upper surface of the cold air guiding plate to guide the cold air flowing along the upper surface of the cold air guiding plate in a direction toward the lower surface of the ice making tray.
 2. The apparatus according to claim 1, wherein the cold air guiding device further comprises first and second side guiding portions extending upward from opposite sides of the cold air guiding plate, respectively, to allow the cold air to flow in a space defined between the lower surface of the ice making tray and the upper surface of the cold air guiding plate.
 3. The apparatus according to claim 2, wherein the cold air guiding device further comprises a third side guiding portion having opposite ends connected, respectively, to first ends of both the first and second side guiding portions, and the third side guiding portion comprising a cold air inlet to be connected to a cold air duct.
 4. The apparatus according to claim 3, wherein the cold air guiding device opens at an opposite side of the third side guiding portion.
 5. The apparatus according to claim 1, wherein the plurality of protrusions are formed lengthwise in a direction intersecting with a flow direction of the cold air.
 6. The apparatus according to claim 4, wherein the plurality of protrusions are formed lengthwise in a direction intersecting with a flow direction of the cold air.
 7. The apparatus according to claim 5, wherein the plurality of protrusions comprise a triangular cross section.
 8. The apparatus according to claim 4, wherein the plurality of protrusions are formed lengthwise in a direction intersecting with a flow direction of the cold air and comprise a triangular cross section, and each of the protrusions comprise opposite ends which come into contact with the first and second side guiding portions, respectively.
 9. The apparatus according to claim 4, wherein the plurality of protrusions are formed lengthwise in a direction intersecting with a flow direction of the cold air and comprise a triangular cross section, and the respective protrusions are spaced apart from each other in the flow direction of the cold air and are alternately arranged at opposite sides of the cold air guiding plate.
 10. A refrigerator comprising: a body having at least one storage compartment; and an ice making apparatus mounted in a partitioned space within the storage compartment, wherein the ice making apparatus comprises an ice making tray to freeze water filled therein to make ice and a cold air guiding device to guide cold air to a lower surface of the ice making tray, and the cold air guiding device comprises: a cold air guiding plate installed below the ice making tray to be spaced apart from the lower surface of the ice making tray; and a plurality of protrusions provided at an upper surface of the cold air guiding plate and adapted to guide the cold air flowing along the upper surface of the cold air guiding plate in a direction toward the lower surface of the ice making tray.
 11. The refrigerator according to claim 10, wherein the cold air guiding device further comprises first and second side guiding portions extending upward from opposite sides of the cold air guiding plate, respectively, to allow the cold air to flow in a space defined between the lower surface of the ice making tray and the upper surface of the cold air guiding plate.
 12. The refrigerator according to claim 11, wherein the cold air guiding device further comprises a third side guiding portion having opposite ends connected, respectively, to first ends of both the first and second side guiding portions, and the third side guiding portion comprising a cold air inlet to be connected to a cold air duct.
 13. The refrigerator according to claim 10, wherein the plurality of protrusions are formed lengthwise in a direction intersecting with a flow direction of the cold air.
 14. The refrigerator according to claim 12, wherein the plurality of protrusions are formed lengthwise in a direction intersecting with a flow direction of the cold air.
 15. The refrigerator according to claim 13, wherein the plurality of protrusions have a triangular cross section.
 16. The refrigerator according to claim 12, wherein the plurality of protrusions are formed lengthwise in a direction intersecting with a flow direction of the cold air and comprise a triangular cross section, and each of the protrusions comprises opposite ends to come into contact with the first and second side guiding portions, respectively.
 17. The refrigerator according to claim 12, wherein the plurality of protrusions are formed lengthwise in a direction intersecting with a flow direction of the cold air and comprise a triangular cross section, and the respective protrusions are spaced apart from each other in the flow direction of the cold air and are alternately arranged at opposite sides of the cold air guiding plate.
 18. An ice making apparatus comprising: an ice making tray to freeze water filled therein to make ice, and a cold air guiding device having a cold air flow path to guide cold air to a lower surface of the ice making tray, wherein the cold air flow path of the cold air guiding device has a cross sectional area decreasing from the upstream to the downstream.
 19. The apparatus according to claim 18, wherein the cold air guiding device comprises: a cold air guiding plate installed below the ice making tray to be spaced apart from the lower surface of the ice making tray; and a plurality of side guiding portions extending upward from opposite sides of the cold air guiding plate.
 20. The apparatus according to claim 19, wherein the cold air guiding plate comprises a plurality of stepped portions configured such that the heights of upper surfaces of the stepped portions initially gradually increase and again, gradually decrease from the upstream to the downstream.
 21. The apparatus according to claim 18, wherein the cold air guiding device comprises a plurality of triangular ribs formed in the cold air flow path to connect an upper surface of the cold air guiding plate and one of the side guiding portions to each other, for creating an eddy of cold air.
 22. The apparatus according to claim 21, wherein the plurality of triangular ribs gradually increase in size from the upstream to the downstream of the cold air flow path.
 23. The apparatus according to claim 18, wherein the cold air flow path of the cold air guiding device has a cross sectional area initially decreasing and again increasing from the upstream to the downstream thereof. 